[Bug] add_hline and add_vline do not work with datetime and annotation_text

[hidr0]

I am trying to show an hline or vline on a time series.

import datetime
import plotly.graph_objects as go
figure = go.Figure()

figure.update_layout(
    yaxis=dict(
        type="date",
        tickformat='%H:%M',
    )
)

figure.add_hline(
    annotation_text="Recommended Daily Intake",
    y=datetime.datetime.now(),
)

The error I get:

  File "..../.venv/lib/python3.9/site-packages/plotly/shapeannotation.py", line 7, in _mean
    return float(sum(x)) / len(x)
TypeError: unsupported operand type(s) for +: 'int' and 'datetime.datetime'

x is:

>>> print(x)
[datetime.datetime(2021, 12, 2, 14, 3, 29, 780450), datetime.datetime(2021, 12, 2, 14, 3, 29, 780450)]

Which means that sum does not work with datetime.datetime:

>>> sum([datetime.datetime(2021, 12, 2, 14, 3, 29, 780450), datetime.datetime(2021, 12, 2, 14, 3, 29, 780450)])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unsupported operand type(s) for +: 'int' and 'datetime.datetime'

[pratikmondkar]

Facing the same issue. This feature is especially useful for facet grids since it avoids having to add annotations for each facet individually

[Uberi]

Looks like this is related to #3065, which also has a workaround!

[gvwilson]

Hi - we are trying to tidy up the stale issues and PRs in Plotly's public repositories so that we can focus on things that are still important to our community. Since this one has been sitting for several years, I'm going to close it; if it is still a concern, please add a comment letting us know what recent version of our software you've checked it with so that I can reopen it and add it to our backlog. Thanks for your help - @gvwilson